SERVICES - Corrocont Group...DCVG method for locating the insulation defects The size of the insulation defect is characterized by a relative number, the so-called % IR number. This

SERVICESSurvey

ß Corrosion Inspection of PIPELINESß CIPS-Close Interval Potential Surveyß DCVG method for locating the insulation defects of pipe lineß Corrosion diagnostic inspection using the simultaneous CIPS and DCVG methodsß GPS-Global Positioning Systemß Cathodic protection of city steel pipeline systems

ß Stray current interference testingß Soil Electrical resistivity surveyß Soil pH and Redox potential surveyß Pipeline Depth Measurement

ß ECDA/ICDAß Risk Assessment/Failure Analysisß GIS Mapping-Geographical Information System with Map & Database management

NDT – Inspection – Non Destructive Testingß Storage tanksß Aboveground Pipelines & related equipmentß Heat exchanger tubesß LFET scanning inspectionß Ultrasonic, Dye Penetrant , Magnetic Particle Inspectionß Visual inspection, Vacuum Box Testing

Installation of Cathodic Protection Systemß Installation of Turn Key CP Systemsß Remote GSM based Monitoring Systemß Engineering Services

Maintenance of Cathodic ProtectionCP TrainingDesign of Cathodic Protection

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Head office: Hungary, H-1124 Budapest, Szendi u. 1., Tel.: (+361) 214-2980Fax: (+361) 214-2982, e-mail: [email protected], www.corrocont.comOffices: Kuwait † Slovakia † United Kindom

CATHODIC PROTECTION & NDTCORROCONT GROUP

CORROSION INSPECTION OF

PIPELINES

Typical application• to evaluate pipeline coating and

define rehabilitation requirements• to locate insulation defects• to collect on and off potential data

along the pipeline• to analyze the protection level with

special regard to the potential valueat the coating defects

• to classify defects• to define weaknesses in the

cathodic protection system• to investigate stray current• to find short-circuited casing, etc.• to propose the necessary action

Corrocont Ltd. developed the integrated intensive method”, the unique combination of the CIPS and DCVG inspection

Intelligent pigging gives us the answer to what happened in the past, the CORROCONT method shows the effectiveness of the current corrosion protection, and estimates the possibility of the corrosion damage in the future.

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CORROSION DIAGNOSTIC INSPECTION USING THE

Simultaneous CIPS and DCVG methods

• every insulation defect belongs tostructure/corrosion potential value

• these measured (real) values serve the basis forthe calculation of the insulation defects (% IR)

• the potential measurement takes place exactlyabove the pipeline

• the measurement needs only one team performingone survey

• we ensure the comparability of the CIPS and DCVGdata by means of the simultaneous readings at agiven place and time the soil-, corrosion characteris-

tics and other factors are the same• based on the data picked up and stored simultaneously by the measurement data register an unified, printed chart is generated to report all information

The simultaneous application of the CIPS and DCVG methods has numerous advantages over other diagnostical solutions:

Intensive measurement diagram

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CIPSThe efficiency of the cathodic protection of pipelines is conventionally determined by the potential value gained from the test points placed regularly every 1-2 km. Only 0.1% of the pipeline route can be evaluated from the measured data since no information is available about the pipe sections between the test points. It is a reasonable effort to measure the potential of the pipe at even smaller distances.

CLOSE INTERVAL POTENTIAL SURVEY

We switch on-off the cathodic protection stations responsible for the inspected pipe section at exactly the same time and syncronously measure the structure and polarizing potential of the pipeline with a special measurement data collecting instrument. The measurement takes place automatically.

The measured values and data considered as important will be stored in the memory. During later processing we make a potential diagram using this data. From the diagram the efficiency of the cathodic protection can be determined along the whole length of the pipeline.

! CIPS measurement

During the CIPS measurement we check the pipe-soil potential every 0.5–1 m whilst walking along above the pipeline.

The DCVG method is directly connected to the cathodic protection of pipelines. The impressed cathodic protection current getting into the insulation defects causes a drop of voltage in the soil.

DCVG method for locatingthe insulation defects

The size of the insulation defect is characterized by a relative number, the so-called % IR number.

This method is also effective in the case of pipelines without cathodic protection by using temporary anodes and CP stations.

At the laying of new pipelines it isrecommended to carry out a DCVGexamination immediately after thepipelaying so that the contractor could repair the possible insulation defects still under guarantee.

The DCVG method is also suitable for the insulation inspection of underground storage tanks.

"DCVG measurement

This potential grade can be detected between the two electrodes placed on the ground with a sensitive mV meter therefore the location of the coating defect can be determined with a precision of 10 cm.

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During pipeline measurements it is extremely important to have the precise location of the structures and measurement data on the pipeline route.

Positioning byGPS technique

At distances of many kilometres this can be realized only by GPS equipment. The precise positioning of the insulation defects is particularly important since this way in the event of an excavation the costs of expensive machine work can be significantly decreased.

To carry out these tasks the Trimble Pathfinder ProXRS equipment has proved to be the best solution. The absolute accuracy of this instrument is better than 1 metre.

ID LONGITUDE LA TITUDE PIPENO.

DEFECTNO.

DEFECTSIZE

GPSDA TA

7 24,514243572 56,283632584 1 10 48 1999.06.308 24,513996945 56,283610959 2 11 95 1999.06.309 24,513391293 56,283695932 2 12 42 1999.06.30

10 24,513041454 56,283761201 2 13 45 1999.06.3011 24,512654514 56,283815351 2 14 55 1999.06.3012 24,512341323 56,283864487 2 15 25 1999.06.3013 24,509766861 56,284219263 2 16 25 1999.06.3014 24,508398741 56,284484192 1 17 42 1999.06.3015 24,508398741 56,284484192 1 18 34 1999.06.3016 24,507624051 56,284610915 1 19 25 1999.06.3017 24,506983248 56,284680759 1 20 26 1999.06.3018 24,506983248 56,284680759 2 21 48 1999.06.3019 24,503384004 56,285162334 2 22 46 1999.06.3022 24,512654514 56,285162334 2 23 80 1999.06.3023 24,512341323 56,285162334 1 24 80 1999.06.3024 24,509766861 56,285162334 1 25 28 1999.06.3025 24,508398741 56,285162334 2 26 32 1999.06.3026 24,494228673 56,285162334 1 27 18 1999.06.3027 24,494228673 56,286532140 1 31 50 1999.06.30

ID

789

10111213141516171819222324252627

LONGITUDE LA TITUDE PPIPENO.

DEFECTNO.

DEFECTSIZE

GPSPPDA TA

CIPS, DCVG, GPS combined measurement #

The device continuously receives correction signals from the Omni-star satellites thus the submetre precision is calculated at the very site, and further pro-cessing is unnecessary.Also the instrument can be used anywhere in the world and therefore, there is no need for a base station network.



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Stray Current interference testingSpecially stray currents arising from DC train, AC power lines and foreign CP system. Static CP survey is used to detect these dangerous interferences.All cathodic protection systems make currents flow through the electrolyte in order to achieve a certain protection level for the protected structure. These currents may bring about earth current corrosion in structures from neighbours. This is called interference from cathodic protection systems.

Important discriminating the effect of different potential fields like, stray current, foreign CP and coating defect potential gradient.

$ 24 hour survey of static ac interference

$ 24 hour survey of static dc interference due to trains

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Soil Resistivity SurveyIn situ soil resistivity measurement is used to detect the aggressivity of soil. CORROCONT provides both the “Wenner four pin method” and the “Electromagnetic method”. Soil corrosivity is based on NACE and BS classification.

Soil Electrical Resistivity ClassificationSoil Resistivity (ohm-cm) Soil CorrosivityUnder 1,000 Severe1,000 - 5,000 Corrosive5,000 - 10,000 Moderately CorrosiveAbove 10,000 Slightly Corrosive

!The soil corrosiveness is classified based on soil electrical resistivity by the British Standard BS-1377 as follows

$Soil resistivity survey graph

Soil electrical resistivity indicates the relative capability of the soil to conduct electrical current and it is a main indicator in deter-mining corrosiveness of the soil. This is generally recognised as the most significant soil charac-teristic with regard to corrosivity of the soil. Soil resistivity can change dramatically with mois-ture content. Soil, which has a high resistivity when it is dry, can have substantially lower resistiv-ity when it is wet or saturated depending on factors such as pH and chemical content.



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Soil pH SurveyThe pH provides a general guide to the nature of possible corrosion. Acidic soils are corrosive. Neutral soils are optimal for the development sulphate-reducing bacteria. Alkaline soils are generally benign, however, exceedingly high pH values can lead to low electrical resistivities. Corrocont offers pH readings and analysing of soil samples from pipeline depth.

The degree of acidity or alkalinity of a soil is expressed as the pH, a value that represents the logarithm of the reciprocal of the hydrogen ion concentration. A pH value of 7 indicates neutrality; lower values, acidity; and higher values, alkalinity. Terms used for soil classification based on pH are defined as follows$

High alkalinity lowers electrical soil resistivity and increase soil corrosivity. Certain corrosive substances in the medium (e.g., chloride ions) and mechanical effects can destroy sur-face films locally, leading to intensive local corrosion such as pitting and stress corrosion. Hence, maintaining adequate cathodic protection is always recommended.

Development of acidity in soils is a result of the natural processes of weathering under humid conditions. In regions of moderate rainfall, soluble salts do not accumulate except where soil waters seep to lower levels and collect in depressions. However, in regions of high rainfall, not only are soluble salts removed from the soil but the absorbed bases normally present in the colloidal materials of the soil are partially removed, and

result in increased acidity. The processes eventually give rise to the condition known as soil acidity. The depth to which this leaching of the bases occurs varies with rainfall, drainage, type of vegetation, and nature of the material present.

Extremely Acid Below 4.5Very Strong Acid 4.5 to 5.0Strongly Acid 5.1 to 5.5Medium Acid 5.6 to 6.0Slightly Acid 6.1 to 6.5Neutral 6.6 to 7.3Mildly Alkaline 7.4 to 7.8Moderately Alkaline 7.9 to 8.4Strongly Alkaline 8.5 to 9.0Very Strongly Alkaline 9.1 and Higher

Soil Classification Based on pH

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Depth DiagramThe depth of cover at defect epicentres are measured and recorded. The measureddepth of cover (vertical axis) is plotted against distance along the project pipeline (horizontal axis) in a line-type chart.

All the information can be integrated in our GIS Mapping System.

Pipeline Locating and Depth MeasurementIdentification of the pipeline subject to CIPS/DCVG survey is essential. In many cases there are many parallel pipes situated closely in the ground. CORROCONT applies high precision pipe locators based on advanced technology to identify pipelines and to determine how deep they are. Our techniques enable a buried pipe to be reliably located and identified from the ground surface, providing a depth of cover reading without the need to dig a hole or penetrate the ground.

The transmitter of the pipe-locator is always connected to the closest CP test station for optimum signal distribution. Above the located buried pipeline, thereceiver is set to measure a depth to the centre of the pipeline. The Pipe depth ismeasured at each coating defect and many other locations consider important.



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ECDA & ICDA PROCESSES FOR OIL AND GAS PIPELINES Safe and continuous operation of underground pipelines is a matter of primary importance in the oil, gas and chemical industries. Failures by corrosion are one of the major and most frequent causes of incidents and environmental disasters worldwide.

External Corrosion Direct Assessment (ECDA) and Internal Corrosion Direct Assessment (ICDA) are structured processes that intend to improve safety by assessing and reducing the impact of internal and external corrosion on pipeline integrity. The main goal is to identify and address corrosion activity, to repair corrosion defects and remediate the cause, and to prevent corrosion defects from growing to a size that is large enough to impact structural integrity. NACE already issued the Standard and Recommended Practice for ECDA and Standard for ICDA.

When new Standards or Recommendations are announced, it is always difficult to find the connection between the requirements of the Standards and the meantime developed new technological tools. In most cases we are loosing

some years, before the equipment manufacturers are converting their systems for the new demands. Our advice is, to analyse all the available technologies with their limitations, and to combine them in a good way to provide the necessary information. Our company has already developed the practical solutions for the Direct Examination, and we

would like to share our findings with our clients during projects. Our main goal is to show a technical package for the ECDA and ICDA processes which is economical, easy to apply and accurate.

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Risk Assessment& Failure AnalysisThink about the Risk assessment, DO NOT FORGET:• A hazard is anything that might cause serious problems, such as: – Internal & External corrosion defects

– Stress corrosion cracking– Incorrect operation– Third party damage– Weather & outside forces

• The risk is a chance high or low thatsomebody and something might be indanger by these and other hazards.

Adverse consequences:• environmental contamination• operation safety• disaster• reconstruction and recovery costs• compensation

Risk AssessmentThe purpose of risk assessment is to identify and quantify the risks associated with pipeline and storage tank operation. CORROCONT applies a risk assess-ment method that determines failure probability and ranking for pipelines, storage tanks and other equip-ment operating in refineries and chemical plants.

How to assess the Risks • Identify the hazards & threats• Decide what could be in danger and priorities

the levels of hazard• Evaluate the Risk and decide on precautions• Record findings and implement them• Review the assessment and update if necessary

To assist in the budgetary process, once this assessment is complete, the inspected structure is prioritized by level of risk. The level of expenditure is determined by several factors, such as: • Effect on national security

• Safe, reliable operation• Compliance with legislative requirements

CORROCONT has extensive, in-depth expertise and experience in risk assessment.



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Risk Assessment& Failure AnalysisFailure AnalysisCorrosion Failure Analysis and Risk Assessment are our specialities. We determine how and why equipment, metals, alloys fail, as well as performing complete, thorough investigations to determine the fitness for service of equipment that has deteriorated due to corrosion, fracture, mechanical damage, or exposure to fire.

"Failure" means that a component has become completely or partially inoperable or has deteriorated so that it has become unreliable or unsafe for continued service.

Failure analysis is the science of determining

how and why a component has failed, due to either mechanical or corrosion means, with the goal of

preventing additional, similar failures. Simply verifying the

failure mode is sometimes of little practical use. It is also important to determine what factors influenced the failure or "why" it failed. The "why" of failure analysis is the driving force behind "root cause" failure analysis. CORROCONT Ltd has extensive experience in executing failure analysis to the study of mechani-cal and corrosion failures.

Complete materials engineering services include failure analysis, risk assessment corrosion control and prevention, API 579 fitness for service assessments, API 580 risk based inspection program development, API 653 storage tank assessments and material selection.

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GIS& Database ManagementFunctionality of GIS The software is developed as an integrated system and integrated database for pipeline operators. Pipeline route maps and all related pipeline data are stored in the system. Analysis of the data allows safe operation and optimized system rehabilitation.

GEOGRAPHICAL INFORMATION SYSTEM

• GIS Mapping of pipelines,with sub-meters GPS accuracy

• Pipeline furniture databasewith drawings

• CIPS + DCVG results• Intelligent Pigging results• Excavation results• Remote Monitoring System,

control and analyzing module• ICCP maintenance module• Database of rehabilitation• Management module• Urgent works and problems• Additional information

Goals & Achievements• To extend the lifetime of pipeline• Keep safe & healthy enviroment• Avoidance of disasters• Optimized operation cost• Reduced and optimized

engineering time• Easy decision making

Integrating results of different inspection techniques and geographical data into one single software

Modules:

Other relevant InformationSoftware can be customized to any clients needs.



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Cathodic protectionof city steel pipelinesystems

Phases of work• previous CIPS and DCVG examinations along the pipeline• preparation of the cathodic protection design• installation of cathodic protection• control and commissioning measurements

by CIPS method• system adjustment

Advantages• the entire cost of cathodic protection is only a fraction of the complete pipeline rehabilitation/exchange• prevents pittings and soil corrosion• cuts the operational costs of the system• checking of the CP system can be carried

out simply, systematically• dangers of stray current corrosion can be

detected and stopped

Cathodic protection is the most effective and most cost-effective way to prevent soil corrosion. CORROCONT guarantees the effective protection in town with the distributed anode system.

! City cathodic protection station

$ Measurement for the design

CIPS diagram of a stray current area

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CATHODICPROTECTIONENGINEERING

Field of CP• Construction• Inspection• Supervision• Project management• Consultancy

Corrocont the world leader CP company.



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OF CATHODICPROTECTIONDESIGN

Design• Temporary Cathodic protection• Sacrificial Anode System• Impressed Current CP for Tanks

– Internal CP– External CP

w GRID System for New Tanks w Loop System for NE Tanks w Distributed System for existing tank• Impressed Current System for Pipelines

– Deep anodes– Shallow anodes

• Acquisition of land• Ability to latch on to any phase of project• Remote Monitoring System• Modification & Upgrading

of existing CP system• Project plan included time,

mile stones, resources & budget

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ESMaintenance of cathodic protection Transformer Rectifiers monthly/quarterly

Test post & Route markers yearlyRemote Monitoring system regular, optionsQualification

– Casing– Isolating joints yearly– Interference testing/survey– AC/DC stray current testing

Reporting-Solution-Reparation as requested

Maintenance

Maintenance and Repairing of Transformer Rectifiers Maintenance of Transformer Rectifier Unit at least once

every 3 months:• Clean and tighten all bolted current – carrying connections.• Check Ventilation, lighting, cooling system, room installation, equipment basement, etc. of the rectifier room.• Checking the indicating meters for accuracy.• For coil immerse unit the oil level and clean-

liness shall be checked. The oil should be clear and nearly colourless.• If oil is murky or cloudy, it should be replaced with good grade of standard Transformer Oil.• Replace damaged and faulty spare parts.

Routine maintenance and checking of the system including Test Station• Cleaning of electrical connections and contact points with the required spray.• Cleaning and Lubricating of Screws and terminals of the junction boxes and covers, and Repair any broken test post and reposition if necessary.• Check the potential along the pipe line w.r.t. Cu/CuSo4 electrode.• Record the readings for all test points along the pipeline.• Adjust the rectifier output according to the required protection level value.

Qualification• Casing• Isolating joints• Interference testing/survey• AC/DC stray current testing



Areas of Training:• CP design• CP maintenance• CP Survey CIPS, DCVG, GPS• NDT pipe & Tank inspection• Intelligent report system according to API, BS, ES, HS & NACE• Solutions

GPStion

m S,

CATHODICPROTECTION & NDTTRAINING

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Documents

SERVICES - Corrocont Group...DCVG method for locating the insulation defects The size of the insulation defect is characterized by a relative number, the so-called % IR number. This